I can't recommend these wood rings enough but they are a little bit pricier. Also i bought this chalk bag which has helped me a ton with false grip for forward rolls and muscle-ups on rings but i don't think chalk is necessary for non-false grip ring work and even then i can still do a MU without chalk it's just a little harder to hold the FG.

Also my only concern with the PU handles for parallettes is that they aren't tall enough for HSPU and in my opinion parallettes are not necessary to learn L-sits, i would use two chairs and start with a knee tucked L-sit and begin untucking slowly until you get a full L-sit between two chairs and then practice them on the floor. I built these for $35 in two hours on a saturday and they've worked really well for HSPU training, planche training, etc.